There are still bison in the park - the original bison may have passed away at some point, but there are definitely a handful of them living in the bison paddock as of January 2018.
There are definitely American Bison in the "Buffalo" paddock near Spreckels Lake. Fencing had to be fortified in recent years to protect the herd, due to the sad loss of a beautiful calf because someone's dog went under the fence and terrorized the bison. Visitors were foolishly feeding them junk food. The herd is the responsibility of the SF Zoo staff. Best chance of seeing them up close is to quietly walk around the path in back of their area, near the Dog Park and Petanque court.
I just saw 5 of them at thr paddock last weekend.
How sad Todd
That was long time
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